Isolation of Mycobacterium tuberculosis from Sputum Samples of Presumptive TB Patients at Chest Clinic, University College Hospital Ibadan

Tuberculosis continues to impose a substantial disease burden on Nigeria, ranked among the world's highest TB burden countries, with accurate laboratory diagnosis critical to effective case management and transmission control. This study isolates and characterises Mycobacterium tuberculosis from sputum samples of presumptive TB patients attending the Chest Clinic of University College Hospital (UCH), Ibadan, Oyo State, South West Nigeria. Early morning spot sputum samples were collected from 150 presumptive TB patients presenting for diagnostic evaluation. Samples were processed by N-acetyl-L-cysteine-sodium hydroxide decontamination, concentrated by centrifugation, and subjected to Ziehl-Neelsen staining, Lowenstein-Jensen culture, and GeneXpert MTB/RIF assay. Culture positivity was 38 percent, with GeneXpert detecting 44 percent positivity overall, confirming its higher sensitivity. Rifampicin resistance by GeneXpert was detected in 11 percent of positive cases, indicating potential multidrug-resistant TB. Smear-negative but culture-positive cases constituted 19 percent of confirmed TB, underscoring the limitation of smear microscopy alone. HIV co-infection was present in 28 percent of confirmed TB cases. The study underlines the diagnostic superiority of GeneXpert over smear microscopy in this cohort and highlights the MDR-TB burden at UCH. Recommendations include universal GeneXpert access, contact tracing intensification, and integrated TB/HIV services at UCH Ibadan. Keywords: Mycobacterium tuberculosis, GeneXpert, MDR-TB, UCH Ibadan, sputum culture